Remote control system for cranes



R. BOLLAERT 2,434,636

Jan; 20, 1948.

' I REMOTE CONTROL SYSTEM FOR QRANES Filed March 2'7, 1946 2Sheets-Sheetl [rvu/af/an A 6? H013) 2/ SF; 5

I I NVENTOR 4 M/ 52 M2 eemifla/beff.

597 2. BY Z5,

ATTORNEY Jan. 20, 1948. R. BOLLAERT REMOTE CONTROL SYSTEM FOR CRANESFiled March 27, 1946 2 Sheets-Sheet 2 fnsu/af/o/l INVENTOR Fem/Boflaerf.

5/ WITNESSES:

ATTORNEY Patented Jan. 20, 1948 UNITED STATES PATENT *OFFlCE 2,434,636REMmeeoNreeL SYSTEM FOR CRANES" "Remi Bollaert,akla'nd, Calif.,;as'signor to West- .inghouse Electric 'Corporation,' East Pittsburgh,

Pin, acorporation of Pennsylvania Application'll larch 27, 1946, serialndsss zsci trolleys with a trolleypropulsion motor and a ihoist motor'oneach trolley. The appertaining controls are equipped with a relay ystemthat comprises one forward and one'reve'rse contactor and twoaccelerating cohtactors for each motor. Auxiliary timing and sequencerelays may also be provided, butthese do not'en'ter into the discussionof the requirednumber of trolley wires. If, for example,- bothmotorsarethree-phase wound-"rotor motors, then the crane control systemwouldcollvehtibnallyhe designed ln one of the two follow ing ways. v

1. The motors only might be put en the main trolley'structures and themain power" wires carried back to thepprators position in thei' cab. Allof the control equipment is then in the cab. In this ca-se it isnecessary to bring three primary and three secohda'ry conductbrsfromeach motor making-atotal of 24 trolley-wires. lt is possible to makecertain wi'res connnonftoseveral motors but at'best three or perhaps-sixtrolley wires can be eliminated 'bythis'expedientf I I 2. It is possibletomount-the 'controlequip ment directly on the trolley structures andeliminate the necessity "of carrying the individual motor' currents ontrolley wires." With this arrangement it is necessary 'tohave three mainline conductors from whichall' of the motors are fed and to carry thecontrol"wires tothe' master switches in the cab. Conventional practiceis to have one wire common'toall of'thecontrol con; tactor'coils withindividual wires extending to the opposite terminals of the contact'orcoils. Since'sixteen coils are to be operated, it is neces-' sary tohave sixteen gcontrol wires,on common control wire, and three main linewires making a total of twenty.

In contrast to these known systems, it is the aim of my invention toachieve the same control performance with a much smaller number oftrolley wires, thus reducingthe'space taken up by these wires andtheamount and "space of the insulating and other equipment needed toacoommodate these wires along the path o'ftravel of the crane trolleys.I s V To this end, and in accordance withmyinvens Clair ns. (01. 172-179tion, I mount the relays of the control'system' directly on th trolley"structure and energize each group of relays appertaining to a particularmotor through a circuit means, such as-a transformer, which'is alsomounted-on the trolley. All relays 'of each individual r'el'ay grouphave a common lea'd connectedto' one'pole of a separate output 'ci'rcuitof the circuit means" or trans- -formerjwhileth other pole of thisoutput 'ciri.

'cuit' extends througha trolley'wire to master control contacts at theoperator's place and, by means of these contacts, is selectivelyconnected to one ofa group of trolley wires of which each is inconnection with one of the respective relays of the one-relay group andalso in connection with one of'the respective" relays of the other relaygroup." While these features of y invention will b more tonyunderstoodffrorfn the following description of the: embodimentillustrated in'thedrawing, it may here be mentiohedjthat, by virtue oftheabove men'tioned features,'in the above-"discussed example of 'atwo-trolley crane with four contactors for each motor, only eightcontrol trolley wires in addition to the three powertiolley'wires "arerequired, makingi'a total of only eleven wires as compared with thetwentyfour or twenty wiresfabove'mentioned. A still more appreciablereduction in the number "of trolley wires is, of course, obtainedinsystems withmore than fourc'ont'rol relays foreach motor or with morethan twotrolley'sl In the drawings": 7 Figure "1 shows diagrammaticallya bridge crane with two trolleys. e e V v Fig. Zisa'simp'li'fiedcir'cuit diagram representing the control panels of the twotrolleys'in'con junctionwith thefap'pertaining trolleywir'es and thmaster control devicesto be actuated by the operator in the control cabof the crane, and

Fig. 3 'is'a more detailed circuitdiagram showing the complete controlequipment'for oneof'the two trolleys; I v I I According to Fig. 1, thewheels A of the bridge structure run on rails C so that the structure ismovable perpendiculanto the plane of illustration. Th drive means forpropelling the bridge in this direction are irrelevant to the presentinvention'and henc not illustrated. 'The bridge structurecarries'rails Don which two trolleys El and E2*are' movable transverse to the travelingdirection of the'bridge structure. Each trolley has twomotors HI, TI andH2, T2, respectivelyi; Ihemotors HI and H2 are geared to the cable 'drumof' thehoisting equipment and serve to hoist "and load the respectivecables FI and.

F2. The motors TI and T2 are eared to the wheels of th respectivetrolleys for propelling them individually along the rails D. Eachtrolley has a control panel PI or P2 which contains all relays andassociated electric equipment for controlling the operation of the twotrolley motors. Eleven trolley wires denoted by I through II extendalong th path of the trolley motion, and are mounted on insulators I.These trolley wires connect the control panels of the two trolleys withth master control equipment located in the operators cab K.

The four motors in the illustrated example are of the three-phasewound-rotor type. They receive their primary excitation through thetrolley wires I, 2, 3 which are connected to a suitable source ofalternating-current voltage. The remaining trolley wires 4 through IIserve to control the relays of the trolley control panels in such amanner as to permit an individual operation of the motors.

According to Fig. 2, each control panel PI and P2 is equipped with acircuit device for providing a step-down voltage for a relay equipment.This device consists of a transformer NI or N2 which has two secondarywindings QI and RI or Q2 and R2. The primary terminals of thetransformers NI and N2 are attached to collectors which engage the powersupply wires I and 3. The secondary windings QI, RI, Q2 and R2 have oneof their respective terminals individually attached to four collectorswhich engage the trolley wires II, III, 9, and 8, respectively. Thesefour trolley Wires will hereinafter be referred to as main control wiresin order to distinguish them from the above-mentioned Power supply wiresI, 2, and 3 and the remaining relay control wires 4, 5, 6 and I. Theother terminal of secondary transformer Winding QI is connected to fourrelays IF, IR, IAI and IA2. These relays, represented in Fig. 2 merelyby their control coils, are connected by four collectors with the relaycontrol wires 4, 5, 6 and I.

In a similar manner, the secondary windings RI in control panel PI oftrolley El and Q2 and R2 in the control panel P2 of the second trolleyare connected to three groups of relays denoted by IH, IL, IHI, IH2; 2F,2R, 2AI, 2A2, and 2H, 2L, ZHI, 2H2, respectively.

The four main control wires 8, 9, I I3, and II are individuallyconnected by respective leads 8', 9', I, and II to four master controldevices M2, S2, M I, and SI which are located in the operators cab. Therelay control wires 4, 5, I5, and I are connected to each of these fourmaster control devices. Device SI serves to control the trolleypropulsion motor TI of trolley El, device MI effects the control of thehoist motor HI of trolley El, while devices S2 and M2 serve forcontrolling propulsion motor T2 and hoist motor H2, respectively, oftrolley E2.

The interconnection of the above-mentioned electric elements and theoperation of the system will be more readily understood from thedetailed showing in Fig. 3 which refers only to the trolley EI and theappertaining master control devices SI and Ml.

According to Fig. 3, the propulsion motor TI is in driving connectionthrough a gear box I2 with the drive wheels I3 of the trolley. Thesecondary circuit of motor TI is equipped with resistors I4 and I5, andthe relays IAI and IAZ, serving as accelerator contactors. operate toshort circuit these resistors sequentially under control by theoperator. The hoist motor HI drives the cable drum I6 through a gear I1and is similarly equipped in its secondary circuit with resistors I8 andI9 to be short circuited under control by accelerating contactors IHIand IE2. I

The primary circuit of motor TI is connected through leads 2 I, 22, and23 and appertaining collectors with the power supply wires I, 2, and 3,respectively. This connection is-under control by relays IF and IR whichare arranged as reversing contactors. When contactor IF is energized,the motor Tl is caused to drive the trolley in the forward direction,while the energization of contactor IR will operate the motor inthe'reverse direction. The coils of contactors IA2, IAI, IR and IF haveindividual circuit leads 24, 25, 26, and 21, respectively, in connectionwith four corresponding collectors which engage the relay control wires4, 5, 6, and 1, respectively. Th leads 24, 25, 26, and 27 are also inconnection withthe coils of contactors IHZ, IHI, IL, and IH,respectively. The other coil terminals of relays IA2, IAI, IR and IF areconnected by a common lead 28 with the secondary winding QI oftransformer NI. Similarly, the remaining coil terminals of the group ofrelays IHZ, IHI, IL and IH are connected by a common terminal 29 withthe secondary winding RI of the transformer. The primary circuit of thehoist motor HI is connected by leads 3|, 32, and 33 with the powersupply wires I, 2, and 3, respectively, under control by theabove-mentioned relays IE and IL. Relay IH is a hoisting contactor andso connected as to operate motor HI in the hoisting direction whenenergized, While contactor IL connects the motor HI for loweringoperation.

It will be noted that in Fig. 3 of the drawings separate collectors areshown for the leads denoted by 2|, 22, 23, 3I, 32, 33 and the twoprimary leads of the transformer NI. This manner of illustration ischosen merely for the sake of clarity and convenience, while it ispreferred in practice to use only three collectors for all these leadsand to attach them properly to the primary circuits of the two motorsand of the transformer.

The master control devices SI and M I, as shown in Fig. 3, correspond tothe above described showing in Fig. 2. These master control devices arerepresented as drum type controllers, each having an ofi position, threesteps in the forward or hoist direction and three steps in the reverseor lowering direction.

In the off position of the two master controllers, asillustrated in Fig.3, the two groups of relays appertaining to the motors TI and HI,respectively, are deenergized because the circuits of the secondarytransformer windings QI and RI are interrupted in the mastercontrollers. When controller SI is placed in the first forward position,the two leads I and II are connected with each other by the contactfingers and contact segments of this controller. As a result, a circuitis closed from secondary winding QI through lead 28, forward contactorIF, lead 2'1, relay control wire 1, lead '1, master controller SI, leadII, and the main control wire I I. Consequently, the relay IF isenergized and closes its contacts, thus causing the motor TI to startaccelerating in the forward direction. When controller SI is moved toits second forward position, lead 5' becomes connected to lead I I, sothat a circuit is closed from the secondary transformer winding QIthrough the trolley wires 5 and I I, thus inserting the acceleratingcontactor IAI int the circuit of winding QI. Contactor IAI closes itscontacts and thereby short circuits the resistor M and the secondarycircuit of motor Tl, When controller Si is placed in its third for-wardposition, lead t and relay control wire l'becomeconnected to lead H andmain control wire l i, so that now the accelerating-contactor Hat isenergized through leads 24 and 28 from secondary transformer winding Ql.Gontactor 4A2 short circuits the secondary resistorslii, thus causingthe motor Ti to accelerate to maximum speed.

Whenthe controller Si is turned from the OE position to its first,second and third reverse positions, the contactor 5B is energized tooperate themotor in the reverse direction, and thereafter-theaccelerating ccntactors lAi and IA2 are sequentially energized to shortcircuit the resistors Mand E5 in the same manner as de scribed in theforegoing.

l/Vhenthe master controller Mi is moved from its illustrated oilposition to the first position hoist, the main control wire it isconnected through leads it and i. As a result, the circuit oftheseoondary winding B! is closed through lead 21, hoisting contact-orll-l, lead 29 and trolley wires 1% and 1. 'Contactor lI-I picks up andstarts the hoist motor H l in the hoisting direction. When controller Miis moved to its second posi tion hoist, the main control wireappertaining to transformer winding Rl becomes connected to lead 5 andrelay control wire so that now the accelerating contactor tilt isenergized through leads 25 and 29. Contactor ll il short circuits theresistors 18 for further acceleration of motor H I. When controller Mlis moved to its third position hoist, lead fii' and trolley wire ibecome connected to the main control wire so that now a circuit isclosed which includes the transformer winding Ri, the lead the contactorEH2 and lead 2d. Contactor EH2 short circuits the resistors 59 for fullspeed operation of the hoist motor HI. When controller Mi is turned fromits off position to the lowering positions, the contactor lL becomesenergized from transformer winding N l through main control wire id andrelay control wire 5. Further details of the con troller elements to beeffective during the lowering operation are not illustrated in thedrawings, because these details are not essential to the presentinvention and may be given a variety of known designs depending uponparticular requirements.

In order to obtain the above described performance of trolley controlsystems according to the invention, the following conditions should beobserved.

Each oi the circuit devices represented by'transformers N I and N2should have its output circuits so connected that the trolley wires iii,H or s, 9, connecting the transformer secondaries with themaster-controller, have the same instantaneous polarities. This isexemplified by the (-1-) and signs indicated at the secondary windingsRI and Q1 of transformer Ni in Fig. 3. If this con dition is-notobserved, an undesired voltage-doubling connection will occur which mayresult in an untimely actuation of all eight illustrated relaysappertaining to motors Hi and Ti. If this should occur when testing theequipment, the connections of one secondary of one or bothtransformers'need merely be reversed so as to impart to all four "maincontrol wires the same instantaneous polarity.

All relays used in the system and controlled through the trolley wiresshould have about the same pick-up voltage as obtained, for instance,

by using relay coils of substantially identical am-' pere turns;-org--if some rel-ays -aredifferent as regards pick-up voltage; electricinterlock corrtacts (as-exemplifie'd anddescribed below) should beprovided to secure the above-described proper above mentioned operatingcircuits "for the I respective rela ys, seme additional paralleloonnectionswill occur during the'operation(lithe-master controlswitches. For instance, when ir'r'l ig. 3 the master 'switch sl isplaced in first position -forward,'=t'he relay IF willbe properlyenergized from transformer'winding Qi'. However, a num- 'ber of parallelcircuits willalsobe closed, suc-h as the one: extending from wire 1through the coils .of relays II-I; IE1. and IA! to Q5 and wire H,

lead H, switch "-rSl," back to wire ll. Another circuit can betracedhf-rorn wire 7 through relays 2F, 2R, lR'to secondary'Q-etc.Hence,' aside from the properly energized relay W, the other relays willalso receive some excitation; Since these other relays; in thefirst-mentioned parallel circuits, areseries-connected ingroups of two,

three or more, the voltage impressed'on' the coils of'the-other relaysis considerably below-normal. Hence, if all coils-are substantiallyalike and'rated to pick up at a voltage-above the'hig-hest individualvoltage drop (42%) occurringv/ithin' the parallel circuits, only theproperrelays will respond in any selected position of the masterswitches.

As mentioned, if it is desired to use relays with diirerent respectivepick-up voltages, an undesired operation of non-selected relays canbe-prevented by interlocks so arranged that one relay,

.when responding, disconnects the coil circuits of one or more otherrelays that are not supposed to operate. Such interlock circuits arewell known for relay control systems, and an example will be describedpresently.-

In the embodiment, as shown in Fig.3, the reversing cont'actors IF andIR are equipped with interlock contacts which prevent one of theaccelerating relays [HI and [H2 to become energized simultaneously withthe operation of the propulsion motor Tl. In this particular instant,the interlocks have the effect that the hoisting or-lowering speed ofhoist motor H1 i limited to'an amount below the normal maximum when aload is hoisted or lowered while the trolley'is in simultaneous motionalong its track.

Similar interlocks may be arranged between the mastercontrollers, suchas SI and S2 appertaining to different trolleys in order to prevent onefrom actuating the relays to be controlled by the other if thetwotrolleys are to operate simultaneously, However, the latter interlocksare not needed if,--as in the illustrated embodiment", nly These andother details of the illustrated control system are represented for thepurpose of explanation and exemplification, and may be modified invarious respects within the principles of my invention.

For instance, a system according to my invention can readily be extendedto more than two'trolleys or more than four motors, and each motor canbe given a smaller or larger number of accelerating steps thanrepresented in the above described example. It is also obvious that theinvention is not limited to alternating-current motors of theillustrated type but is applicable in general to any type motors to beoperated through trolley wires or through slip rings such as on Whirleycranes. In addition to" the trolley wires discussed above, there areusually some others required for the customary hoist limit switches,travel limit switches, or other protective devices. However, suchadditional wires would also be used in systems of the conventional typeand hence are not pertinent to the present invention.

I claim as my invention:

1. An electric system for controlling a crane trolley from an operator'splace remote from the trolley, comprising two reversiblealternatingcurrent motors disposed on the trolley for propelling andhoisting operations respectively; two groups of relays disposed on thetrolley for controlling said respective motors; transformer meansdisposed on the trolley and having two output circuits each having twoterminals of which one is connected to the relays of one of said groupsrespectively; a group of trolley wires comprising wires for supplyingpower to said motors and transformer means and control wires; selectivecontact means disposed at the operator's place for connecting one ofsaid output circuits through said control wires across the respectiverelays of one of said relay groups to control said propulsion motor; andselective contact means disposed at the operators place for connectingsaid other output circuit through said control wires across therespective relays of said other group of relays to control said hoistmotor.

2. An electric system for controlling a crane trolley from an operatorsplace remote from the trolley, comprising two reversiblealternating-current motors disposed on the trolley for propelling andhoisting operations respectively; two groups of relays disposed on thetrolley for controlling said respective motors; transformer meansdisposed on the trolley and having two output circuits each having twoterminals of which one is connected to the relays of one of said groupsrespectively; each relay of one of said groups having an individual leadconnected with one of the respective relays of said other group, a groupof trolley wires including power supply wires, two main control wiresand relay control wires; a group of collectors for engaging said trolleywires including power collectors engageable with said collectorsengageable with said main control wires respectively and being connectedto said output circuits respectively, and collectors engageable withsaid relay control wires respectively and connected to said respectiveindividual leads; and two master control means disposed at the operatorsplace for connecting said respective main control wires selectively withsaid relay control wires for individually controlling said two motors.

3. An electric system for controlling a crane trolley from an operatorsplace remote from the trolley, comprising a reversible trolleypropulsion motor and a reversible hoist motor disposed on the trolley; afirst group of relays disposed on the trolley for controlling saidtrolley motor and comprising two selectively operable reversingcontactors; a second group of relays disposed on the trolley forcontrolling said hoist motor and comprising two selectively operablereversing contactors; circuit means disposed on the trolley and havingtwo output circuits for energizing said relay group respectively, eachof said group of relays having a common lead connected to one of saidOutput circuits respectively and each of said relays having anindividual lead; a group of trolley wires including power supply wires,two main control wires and two relay control wires; a group ofcollectors for engaging said trolley wires including power collectorsengageable with said power supply wires and connected to said two motorsunder control by said respective groups of relays and beingalsoconnected to said circuit means for providing energization therefor,two collectors engageable with said main control wires respectively andbeing connected to said output circuits respectively, and two collectorsengageable with said relay control wires respectively and being eachconnected to said individual lead of one of said first group of relaysand also to said individual lead of one of said second group of relays;trolley master control means disposed at the operators place andconnected to said two relay control wires and to the one main controlwire appertaining to the one output circuit connected to said firstgroup of relays for controlling said trolley motor by selectivelyclosing said one output circuit through said relays of said first'group,and hoist master control means disposed at the operators place andconnected to said two relay control wires and to the other main controlwire for controlling said hoist motor by selectively closing said otheroutput circuit through said relays of said second group.

4. An electric system for controlling a crane trolley from an operatorsplace remote from the trolley, comprising two wound rotor motorsdisposed on the trolley for propelling and hoisting operationsrespectively and having each a primary circuit and a secondaryresistance circuit; two groups of relays disposed on the trolley forcontrolling said respective motors, each of said groups having a forwardcontactor and a reverse contactor for selectively controlling theprimary circuit and at least one accelerating relay for controlling thesecondary circuit of the appertaining motor; transformer means disposedon the trolley and having two secondary windings each having twoterminals of which one is connected to all said relays of one of saidrelay groups respectively; a group of trolley wires comprising powersupply wires for said motor primary circuit and said transformer means,two main control wires in conductive connection with said otherterminals of said respective secondary windings, and relay control wiresin conductive connection with said two forward contactors, said tworeverse contactors and said accelerating contactors respectively; andtwo master control means disposed at the operators lace for connectingsaid respective main control wires selectively with said relay controlwires for individua-lly controlling said two motors.

5. An electric system for controlling a plurality of crane trolleys froma single operators place, comprising two reversible motors disposed oneach trolley for trolley propulsion and hoisting operationsrespectively; two groups of relays disposed on each trolley forcontrolling said respective motors; circuit means disposed on eachtrolley and having two output circuits each having two terminals ofwhich one is connected to the relays of one of said respective groups ofrelays; a group of trolley wires including power supply wires forenergizing said motors and said circuit means, a number of main controlwires corresponding to the total number of said output circuits andindividually in conductive connection with said respective otherterminals of said output circuits, and relay control wires in conductiveconnection with the respective relays of each 01 said relay groups; andselective master control means for each of said trolleys disposedat theoperators place for individually connecting the two main control wiresthat appertain to each trolley with said relay control wires forindividually controlling said two motors of each trolley.

6. An electric system for controlling a plurality of crane trolleys froma single operators place, comprising two reversible alternating-currentmotors disposed on each trolley for trolley propulsion and hoistingoperations respectively; two

trol wires each being in conductive connection with a plurality ofrelays appertaining to different ones of said relay groups; andselective master control means for each of said trolleys disposed at theoperators place for individually connecting the two main control wiresthat appertain to each trolley with said relay control wires forindividually controlling said two motors of each trolley,

7. An electric system for controlling a plurality of crane trolleys froma single operators place, comprising two reversible wound rotor motorsdisposed on each trolley for propelling and hoisting operationsrespectively and having each a primary circuit and a secondaryresistance circuit; two groups of relays disposed on each trolley forcontrolling said respective motors, each of said relay groups having aforward contactor and a reverse contactor for selectively controllingthe primary circuit and at least one accelerating relay for controllingthe secondary circuit of the appertaining motor; transformer meansdisposed on each trolley and having two secondary windings each havingtwo terminals of which one is connected to all said relays of one ofsaid relay groups respectively; a group of trolley wires comprisingpower supply wires for said motor primary circuit and said transformermeans, a number of main control wires corresponding to the total numberof said secondary windings and individually in conductive connectionwith said respective other terminals of said secondary windings, andrelay control wires each being in conductive connection with a pluralityof relays appertaining to different ones of said relay groups; andselective master control means for each of said trolleys disposed at theoperators place for individually connectin the two main control wiresthat appertain to each trolley with said relay control wires forindividually controlling said two motors of each trolley.

8. An electric control system for controlling two trolleys of a bridgecrane from an operators place, comprising two three-phase wound rotormotors disposed on each trolley for propelling and hoisting operationsrespectively and having each a primary circuit and a secondaryresistance circuit; two groups of relays disposed on each trolley forcontrolling said respective motors, each of said relay groups having aforward contactor and a reverse contactor for selectively controllingthe primary circuit and first and second accelerating relays forcontrolling the secondary circuit of the appertaining motor; transformermeans disposed on each trolley and havin each two secondary windings,each of said secondary windings having two terminals of which one isconnected to the relays of one of said respective group of relays; agroup of eleven trolley wires including three power supply wires forsaid motors and said transformers, four main control wires forconnection to said other terminals of said four secondary windingsrespectively, and four relay control wires in conductive connection withsaid forward contactors, reverse contactors, first acceleratingcontactors and second accelerating contactors respectively; andselective master control means for each of said trolleys disposed at theoperators place for individually connecting the two main control wiresthat appertain to each trolley with said relay control wires forindividually controlling said two motors of each trolley.

REMI BOLLAERT.

